fstab mounter looks for mount_zfs binary in /Library/Filesystems/zfs.fs/Contents/Resources/

[jonhermansen]

I'm finally able to share my zpool across multiple OSes (Linux, FreeBSD, macOS) but I hit a few snags in the process. One of which is that, across the various platforms, I need to use different mount points depending on what OS I'm booted into.

Therefore, I have set all of my filesystems to legacy mountpoints, and from Linux and FreeBSD, I'm able to specify where each FS will be mounted to (at boot time) using fstab.

I tried to replicate this same behavior on macOS today, and I found that after setting up my fstab file, running mount -a, I received an error about a missing file:

$ sudo mount -a
mount: exec /Library/Filesystems/zfs.fs/Contents/Resources/mount_zfs for /mnt/freebsd: No such file or directory

Note that it was not the /mnt/freebsd directory that didn't exist, it was the mount_zfs executable that was missing. The /etc/fstab entry in question looks like this:

tank1/ROOT/12.0-CURRENT-up-20190131_131339	/mnt/freebsd	zfs	rw	0	0

I copied the mount_zfs binary from /usr/local/bin into the /Library/Filesystems/[...] directory for zfs, and now mount -a succeeds:

$ sudo cp $(which mount_zfs) /Library/Filesystems/zfs.fs/Contents/Resources/
$ sudo mount -a                                                             
Feb  9 22:25:35  mount_zfs[24433] <Notice>: zfs/mount_zfs manual_mount

If the same mount_zfs binary could be copied at install time to /Library/Filesystems/zfs.fs/Contents/Resources/mount_zfs then this use case could be supported.

[lundman]

I think it is supposed to create a symlink there - or copy it, I'll check the installer script